Hydrotest after field PWHT

[nsbreddy]

Hi,
I have come across a case where we have a wet sour vessel field Heat treated (PWHT), originally not heat treated. Due to certain process conditions it was decided that the whole vessel shall undergo field PWHT. Reactor is made of carbon steel and built approx. 30+ years back. All other design and operating conditions have not changed.
My query, is it mandatory to perform field hydrotest?

 

[r6155]

See ASME PCC-2
Repair of Pressure Equipment and Piping.

Regards

 

[GD2]

nsbreddy,

Hydrotest is common in pressure vessels- whether at new or after repair.
I am a bit curious. Was the PV not designed for sour service originally? Why PWHT now?

GDD
Canada